I live in Washington DC area, I am cool not to leave?

The Pentagon e.g. would be a legitimate target for Iran and if in their operations against the US they know that your neighborhood is a military target then they can and should warn you and allow you to leave. I doubt that the US military stores rockets in your basement but if they are then that would be a concern. That said if you were in range of Iran's rockets I don't think they'd worry much about e.g. firing cluster munitions on Washington DC like they do on Tel Aviv or Israeli cities.